Tuesday, July 29, 2014

These cool NASA animations of Saturn show its spectacular light shows. These are converted from observation of the Hubble Space Telescope.

Saturn has a magnetic field much stronger than Earth’s. Auroras also have been observed elsewhere in the Solar System, such as on the surfaces of Venus, Mars and even on certain moons (e.g. Io, Europa, and Ganymede).

The Saturn light show is created in a couple of different possible ways. One is when solar wind particles are channeled into the planet’s magnetic field toward its poles, where they interact with electrically charged gas (plasma) in the upper atmosphere and emit light. It is sort of like static electricity from your carpet.

Auroras on Saturn can also be caused by electromagnetic waves generated when its moons move through the plasma that fills the planet’s magnetosphere. The main source is the small moon Enceladus, which ejects water vapor from the geysers on its south pole, a portion of which is ionized. The interaction between Saturn’s magnetosphere and the solar wind generates bright oval aurorae around the planet’s poles observed in visible, infrared and ultraviolet light. If you could see all those spectra with the naked eye, it would be quite spectacular.

The aurorae of Saturn are highly variable. Their location and brightness strongly depends on the Solar wind pressure: the aurorae become brighter and move closer to the poles when the Solar wind pressure increases.

Saturn is turning into a favorite spot in the Solar System for these kinds of animations because, well, it's scenic. Expect more of these animations.